swart



- W. G. SWART, F. A. JORDAN, E. W. DAVIS AND T. B. CDUNSELMAN.

APPARATUS For; MAGNETIC slzlNG AND GRADING' oF-omz.

APBLlCATlON FiVLED SEPT. H. 1917.

1,380,871. Patented Jun@ 7,1921.

4 SHEETS-SHEET 2.

w. G. swAIIT, F. A.l JORDAN, E. w. IIIIvIs AND I. COIINSELIIIIAN.

APPARATUS*v FOR MAGNETIC SIZING AND GRADING 0F OBE. APPLICATION FILEDSEPT. II, Isij.

1,380,871; Patented June 7,1921.,

4 sIIEEIs-s'IIEET 3.

w. G. swAIII, I.'II JORDAN, E. w. DAVIS ANDI. B. GOUNSELMAN.

APPARATUS FOR MAGNETIC SIEING ANDy GRADING OFOBE.

APILICATION man SEPI.v I I. e917.

1,380,871.. Patented me 7, 19:21.-

elevators and the screens areworn yout in To all/whom t may concern." fv UNITEDA STATES? PATENT OFFICE.

wALrEnG. swARr, FRED A. JORDAN, 'nnWRD w.`fDAvIfs, AiIDEHEO'DE .3....COUNSELMAN, oF DiULU'rn;iviINivEsorrA.` f f i Lesoti.

Be it known that we, WALTER Gg. SwAii'r,

FRED A. JORDAN, EDwaiiD W. yDavis, andv Tiinononn B. COUNSELMAN,citizens of the'V United States, residingy at Duluth,.in the i county ofSt. Louis and State ofMinnesota,

have invented certainnew and useful -Im-i provements' in ApparatusforfMagnetic .Sm-

ing and'Gradingfof Ore, ofwhichthewfollowingis a'specific'ation. f Y z"1 This invention relates to improvements in apparatus for the magneticsizing and grading of ore, and has for its object to`provide apparatusVfor that purpose by which the` use of belt and bucket elevators, orsimilar devices, and also the use lof sizing screens, may be dispensedwith. `In present day processes and apparatus for the magneticseparationV and concentration @of pres, in

so far as preliminary sizing-'and separation is concerned, bucketelevators are most'generally usedbetween thevfapparatus and thel`different stages, Vand screens'for sizing and grading the ore as tosizeV are vutilized Vbe-k tween the various steps Both the bucket acomparatively short time,idue to the 'abra-y sive and destructive actionof thefbroken;y ore, andv these elements requirefrequent re. placing,which requires considerable expense not only for replacement, but for.the time required therefor, and necessitates the closing down andthrowing out of operationof By our apparatus we are en-i abled to sizeand grade the ere more economi-k thev mills.

of the preliminary sizing, grading, andcrushing. l

Another obj t vide a` separating cobber, or the like, with magnets soarranged as to present a fieldof varying intensity through which thecrushed ore particles pass, whereby it is possible to.

' throughout the drawings. In Fig; 1 is shown a perspective view of ectof our invention isto pro-` described later;

kAriiiitlrrus ron MAGNETIC fsiznvev AND eRfADiivG or y01mv `Y n"vspecivcatoniorf Letters Patent. V133,113,91'litgduneif, 1921.ippiieaupniuea september i1,k i917. @seriai No. 190,719; *j

classify the ore, as described'above and f will lbemore fully explainedhereinafter.r Still'another object of our invention is -to provideapparatus by'which'crushed ore con-k -taining magneticallysusceptiblemate'iial is subjected' to the action of velocity and'magknetic attraction, inorder to "enable us 'tof v separate from'thehigh grade` and valuable ore particles the large sized tailingparticle'sand theksinallersized tailing particles,v andthus enable us todispose ofthese two` sizes as a` by-product for use as railroad ballastand road-building material,1as well as obviating the necessity forfurthers'creenf ingk and Sizing'befo're disposing ofsaid tail' ings.l l,

"pf Infthe `accompanying fdrawingsl kFigure 1 is al perspective viewVofon'e cobbersetf` Fig.l 2 is a side elevation of the same.

Fig. 3 is a diagrammatic view of la wiring arrangement` to permitvariation of the in-j.`

ltensity lof the magnets of Lone cobber.l

Fig, 4 is'adiagrammatic flow sheet, showing4 one karrangement ofmulti-stage apparatus. y ,f f

fFig. 5 is a similar view of a different ar'- rangement; and D 'l Fig. 6is. a similar view of still another arrangement. a I

Like `.numerals refer yto like elements one cobber set, the showingbeing partially diagrammatic for clearness. 10 designates a pulley ordrumfrotating with a hollow shaft 11, which rotates upon the hollowfsleeve or shaft 14.` 12 designates a' driving belt' operating the pulley10. A'belt con-`r veyer 17, 'preferably `of resilient material, such asrubber', to resist the abrasive actiony of the ore particles,.passesaround the pul-v ley 13 and around the cobber drum 15, which is drivenby the hollow shaft 11 and rotates upon the hollow sleeve 14. 18 isachute leading from the preliminary crushing rolls Vand 'deliveringtheore as it is first crushed from the rollers-,see Fig.` 4, forexamples-fupon the belt 17, by which it` 'is conveyed to `thecobberdrum, as shown i in Fig. 1. Partitions -,A,\B yare shown. inFigs. 1l and2 and Z, respectively, as will be morefully StationaryV magnets, Agen#-erally indicated by numeralv 20 and specifi-v yas providing deposit binsor spaces X, Y, i

cally indicated bythe letters a, b, c, ai, e, f, and g, are provided, asshown in Fig. 3, the same being connected by the magnet yoke 20 carriedupon the hollow sleeve 16. The main branch or feed wires 21, 22 areprovided, and excitation current wires surroundvr each' of the magnets2O and are located in parallel between the :feed Wires 21 and 22. InFig. 3 we have Shown a rheostat 241 as being provided in each of themagnet circuitsfor the purpose of `varying the current flow through thecoils 23 and permitting individualregulation of the intensity of eachmagnet. It will be obvious that any number of magnets of any desiredexcitation may be provided without departing from the spirit of theinvention.

In Fig. 3 we have shown magnets c, b, and f, g as being more stronglyexcited than the intermediate magnets, for a purpose Yhereinafter to'bedescribed. y.

lIn Fig. 4i is illustrated a multi-stage apparatus in diagrammaticVform, in which crushing rolls 7 receive the ore by the chute 6, throughthe medium oi the conveyery 5, from thebin or the like-not shown. Asstated above, after crushing by the rolls 7, the crushed particles ofthe desired size, for example, two inchmesh, are deposited upon theresilient belt 17 and carried tothe first cobber 15, by'wh ich atwo-part-separation apparatus. All'the other particles are deposited bythe shed 31 upon the conveyer belt 170, for conveyance to the secondcobber drum 150, which also effects a two-part separation, whereby largetailing particles of low magnetic susceptibility are carried by the-shed32 to a collection receptacle 32, thus dispensing with their furthercrushing and treatment by this apparatus, and thereby increasing itscapacity in the further stages of operation. All other particles arecarried by the cobber drum 150 and shed 32 to' a second set 'of crushingrolls 70, which deposits them as crushed to a smaller size upon thesecond conveyer belt 170, by which they are conveyed to a third cobber151, similarfto the cobber 15, and a two-part separation is againeffected, as described above., `Si'ibsequent operations similar to thosefirst described are carried on according to the nature and necessarytreatment of the' ore until the final preliminary stage,

where the last cobber drum 155 finally sepa-Y rates the ore particles,depositing the tail,-

ings upon the conveyer or the like, and the inal fines upon the conveyery for removal to the ball mill-notshoivn.Y

In Fig. 5 is shown another iiow sheet embodying a slightly modilied'form of appara-I tus which utilizes the conveyer 5, chute 6, preliminarycrushing-rolls 7, chute 18, and iirst cobber 15, as in the apparatus ofFig. 4. The cobber 15, however, in the Jform shown in Fig. 5 is operatedAto effect a three-l part separation, as inthe structure of Figs. 1 to3, save that while the lines are collected in thev bin 5() and rthemiddlings carried by shed 51 to the second set of rolls 70, the largetailing particles are deposited by shed 52 upon the :conveyer belt 170for a second treatment by cobber 150, which separates the large tailingsinto two parts, one of which consists or' the particles of low magneticsusceptibility. These particles are deposited by shed 150 in thecollection bin or space 32', While the large tailing particles,considered ot suilicient metal content to render their further treatmentdesirable, are `carried by the shed ,150 to the rolls 7() with themiddlings. Subsequent stages utilize the same apparatus as that iirstdescribed to perform subsequent similar operations, the retainedmiddlincs in each instance bein@ crushed smaller and smaller until thefinal separation takes place by means or" cobber 155.

In Fig. 6 is shown still another form or arrangement of apparatus inwhich a single cobber drum is utilized in each stage .of operation aftercrushing of the ore by pre'- liminary crushing rolls 7, and its depositby chute 18 upon the conveyer belt 17 for conveyance to the iirst cobberdrum 15, which, asin the showing of Figs. 1 to 3, effects a three-partseparation, the fines and small particles being deposited in bin Z, thelarge tailings being deposited in biirX, and the middlings and allparticles of varying metal content being carried by the partitions A, Bto the second set of crushing rolls 70. These operations are repeated asmany times as are desirable until iinal separation by the last cobberdrum 155, as in the other forms e. magnetic poles; and the force ofgravity. In thetravel of the particles to V'the cobber drum, were themagnets not eXClteCl iis the particles, save' yas v-aiiected by theresisti ance to their movement by the air through which they pass,wouldbe' projected out-v wardly in va path approximating a para-` bola. Thelarge particles are naturally less aiected by the resistance of the airand travel farther from thefcobber drum than lwould the smallerparticles, and more closely approximate ,this-` parabolic trajec wouldbe( affected to little or no extent by the magnetic attraction, and areyprojected a substantially greater distance from the cobber than theparticles containing iron ore, for example-such as magnetite. y'Largeparticles of low or middling grade,'as stated, will be attractedto thecobberry drum by the magnets according tothe `distance of their magneticcenter of attractionfrom the magnet poles. In fact, alll particleshaving any magnetic susceptibility will be so affected, and the smallhigh grade particles, being in coin,- paratively close proximity to thesource of magnetic attraction, will be retained in close contact withthe cobber drum and, by proper regulation of the magnet intensity,themiddling particles, especially those of comparat tively large size, willbe carried through a lesser arc of travel by the cobber drum,

owing to the action of the momentum, the force of gravity, and thecomparatively weak attraction exerted upon them, while the small highgrade particles or fines will be carried through a greater arc oftravel, and advantage is taken of this fact to efect the three partseparation above described.:

This efect may be enhanced jby the proper regulation of the magneticintensity,- as shown in Fig. 3, for example. The rheostats controllingthe current flow around the different magnets and are so arranged as toy present a comparatively strong magnetic lattraction of the magnets 0:,b, which first exert attraction upon the ore particles as they areconveyed to the cobber. This relatively strong attraction will notaffect the largek low grade and tailing particles of low magneticsusceptibility, which will be thrown outwardly as described above. Itmay, however, be of suiiicient strength to cause the middling`particles, especially those of large size, to beheld by the cobber drumuntil the large tailingparticles have been rejected, and 'when in thecourse of its travel the excitation of the less excited magnets c, d,and e is encountered the force of gravity and the momentum is suiicientto counteract the attraction of the magnets upon these larger middlingparticles, and they will accordingly drop in the bin B, as described.This weaker excitation, however, will be suflicient to retain the finesand particles of great magnetic susceptibility upon the cObberdrUm,'although7 the excitation may be .so `controlled as to permit 'largeparticles of relatively great ymagnetic susceptibility yto passvwiththemiddlings as requirlng tur-1y ther crushing. As the magnets f and gexert their attraction" upon kthe particles which still cling tothecobber drum, they` will retain the fines and particles of greatymagnetic susceptibility until the middlings and; i

largefretained `particles haveall `been rek .jected or allowed yto drop.so that the fines rmay be readily separated and deposited in the bin Zas they pass beyond the attraction of the magnets. This three-partseparation :permits thei early and preliminary rejection of the' largetailing particles, asstatedabove, which ydoes away with the necessityyfor furthe'r treatment and crushing by this apparatus, therebyconsiderably increasing the capacity of the apparatus, by eliminatingthematerial which-it is' unnecessary further `to treat and crush.y Thesamer is true of the linesor high `grade concentrates which may betakendirectly to the final crushing.

element, suchias ra ball mill, previous,u to

the final concentrationa- By utilizing our apparatus 1n an initial'stage, separating the large tailing particles from the remainder of thecrushed ore, we

obtain relatively large tailing particles capable of use as railroadballast, while the ysmaller tailing particles are carried into the Vbinor space with middlings and larger high grade particles. A second stageofy treatment in a similar manner will result in the reduction of thesetailings of'smaller size,

nets may be varied-all without departing rfrom the scope or spirit ofour invention as defined in the appended claims.

What we claim is l. In apparatus of the class describeda rotatable drumand a series of electro-magnets distributed in arcuate form within andadjacent the periphery of said drum and con 1 2;.,In apparatus` .of thecla-ss describedY a rotatable drum aVV series of electro-magnetsdistributed in arcuate form` Within and adjaceni-l the"y periphery ofsaid drum and eo-act ingtherewitlrto attract magnetically susceptibleparticles carried thereto and means to vary the strength of the excitingcurrent of said magnets independently each other as desired.

3. ny apparatus of the class described, a drum, al belt running on saiddruml tof convey ore particles. thereto, a plural-ity of magnets locatedWithin said' drum, saidV magnets being regulable as to attraction', tomagnetically attract midd'ling ore particles and large rately andindependently regulable as tol magnetic strength to withdraw allr savethe tailing particles from the path of the latter and tothereafterWithdraw the fine concentrates fiom the remainder.

y 5. In apparatus of the class described, a drum, means to deliver oreparticles rto said drum, aplurality of magnets located Within said drum,all ofsaid magnets being 0perativev vte attract magnetizable particles,eertain of said magnets being of relatively great excitation, others ofsaid magnets following said magnets of. greater excitation being ofweaker excitation, and certain otherpoi' lsaid magnets following saidmagnets of weaker excitation being of relatively greater eXcitation..

Intestimony whereof, We have subscribed our names. v i

VALTER G. SVVART.

FRED A. JRDAN.'

'ED'l/VARD VV. DAVIS.

THEODRE B. CONSELBAN. Witnesses i Y LYDrA M. l/VooDBRmGE,

H. N. MAGHARG.

